Influence of climate change on a Ghijben–Herzberg lens

SummaryIt is feared that climate change may cause a fatal reduction of thin fresh water pockets under arable land in the low lying western part of The Netherlands, due to an increase of brackish seepage and a decrease of recharge. In order to obtain a first estimate, a formula was derived for the steady shape of a Ghijben–Herzberg lens under an elongated island in the presence of a brackish seepage flux coming from great depth, together with an approximate formula to estimate how long it takes for a fresh water body to adjust to new conditions of seepage and recharge.